Research on pulsed illumination for increased efficiency of plant growth has been going on for over a century. In 1905, Brown and Escombe found, using a rotating sector, that three-quarters of the light can be cut out without decreasing the rate of photosynthesis, and that the photosynthetic efficiency of light utilization in certain plants increased by more than 100% in intermittent light. Warburg (1919) found that Chlorella grew better under intermittent light than under continuous light, depending on the frequency of the light pulse. With a frequency of 4 pulses per minute (0.067 Hz) the improvement was 10% and with a frequency of 8000 periods per minute (133 hz) it was 100%. Emerson and Arnold (1932) were able to improve plant yield by 400% by flashing 50 flashes per second (50 Hz) and making the light period much shorter than the dark period. The photosynthetic efficiency of using pulsed, intermittent light translates into both significant savings in the cost of plant growth for the industrial market and an eco-friendly reduction in the need for electricity in industrial plant grown.
There are many studies that show the advantage in illuminating on plants using LEDs, while illuminating in a predefined wave length, for example only blue photons in the range of 420-470 nm. Illumination using LEDs may prevent the need to cool the area in which plants grow, as the amount of radiation is controlled and limited.